• Fisheries and Aquatic Sciences
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• v.24 no.12
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• pp.394-399
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• 2021

Song-Gang^® bio-stone (SGS) is a microporous crystalline hydrated aluminosilicate which has found various applications because of their very unique physiochemical characteristics such as ion exchange and absorptive-desorptive properties. Significant progress has been made in recent years on applications of these inorganic adsorbents in different industries including agriculture, aquaculture, water and wastewater treatment. This review article intends to summarize the published reports on the applications of SGS in aquaculture industry. SGS application as a feed additive to enhance fish growth and promote their health and nutritional parameters is the most important discussed areas. According to the technical data that are discussed in this review, SGS should be considered as a material with tremendous potential for application in the aquaculture industry. Considerable amounts of research works are under way to explore other opportunities for application of SGS to benefit aquaculture industry.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.3
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• pp.323-329
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• 2016

The effects of dietary antioxidant [saltwort (SW), leek (LK), and dandelion (DD)] supplementation on the growth, body composition, serum chemistry, and challenge test results of juvenile rockfish, Sebastes schlegelii, were determined. In an experiment, 320 fish were randomly distributed into eight, 50-L flow-through tanks (40 fish per tank). Four experimental diets were prepared: the control diet (Con) with synthetic antioxidant: and diets with SW, LK, or DD from natural sources. Each diet was randomly assigned to duplicate tanks of fish, which were hand-fed to satiation twice daily for 8 weeks. After the 8-week feeding trial, 20 fish from each tank were artificially infected with Streptococcus iniae and monitored for 6 days. The dietary additives did not affect survival, weight gain, specific growth rate, feed efficiency (FE), protein efficiency ratio (PER), or plasma chemistry. However, the cumulative mortality of fish fed the SW, LK and DD diets was lower than that of fish fed the control diet beginning 4 days after infection. In conclusion, dietary supplementation with SW, LK, and DD did not affect the growth, FE, PER, or plasma chemistry of rockfish. However, dietary inclusion of SW, LK, and DD lowered the mortality of rockfish following infection with S. iniae.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.5
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• pp.1491-1498
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• 2015

In this study we investigated the effect of vaccine efficacy and immune activities by feeding additives several natural herbal remedies extracts of Sweet Wormwood (Artemisia annua), Galla Rhois, Oriental raisin tree (Havenia Dulicis) and 6-mixed herb to Oilve flounder, Paralichthys olivaceus. Each group of fish fed with the herbal remedies added feed and basic formula during the seven weeks and vaccinated with Edwardsiella tarda Formalin killed vaccine after 4 weeks feeding. Relative Percentage Survival values (RPS) in the group was assessed by the challenge with E.tarda. All groups with the herbal remedies added feed enhanced growth rate, but there were not significantly different in lysozyme activity and agglutination titer. In a challenge experiment with E.tarda, RPS in the all groups feeding additives natural herbal remedies was higher than that of the control group. These results suggest that the natural herbal remedies extracts of Sweet Wormwood (Artemisia annua), Galla Rhois, Oriental raisin tree (Havenia Dulicis) and 6-mixed herb would be effective to enhance efficacy of vaccination to Olive flounder.

• Journal of Aquaculture
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• v.20 no.2
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• pp.114-120
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• 2007

Two feeding experiments were conducted to evaluate the effects of the experimental extruded pellet (EP), commercial EP and raw fish-based moist pellet (MP) on growth of growing flounder (Paralichthys olivaceus). In experiment 1, two replicate groups of the fish (average body weight of $115{\pm}3.2\;g$) were fed one of five experimental diets (EP1-EP5) and MP in circular concrete tanks (4.6 m $\phi$, 0.6 m depth) for 78 days. In experiment 2, in order to evaluate EP in the commercial scale ($8\;m\;{\times}\;8\;m$), flounder (average body weight of $137{\pm}11.4\;g$) were fed one of five EPs (EP1-EP5) used in experiment 1, commercial EP (EP6) and two MEPs (MEP4 and MEP6) as moist pellet types which were made from EP4 and EP6, respectively, by being sprayed with a mixture of water and additives for 80 days. In experiment 1, weight gain of fish fed the all EPs was not significantly different from that of MP. Feed efficiency of fish fed the EP4 was highest, and protein efficiency ratio of fish fed the EP4 and EP5 was significantly higher than that of fish fed the MP (P<0.05). Significant differences were observed in the contents of moisture and crude lipid in the muscle, and moisture in the liver of fish (P<0.05). In experiment 2, weight gain of fish fed the EP4 and MEP4 were highest and feed efficiency showed high tendency in EP4, MEP4 and MEP6. Fish fed the MEP6 showed higher weight gain and feed efficiency compared to those of fish fed the EP6, but there was no difference in those of fish fed EP4 and MEP4. Based on the results of this study, dietary formulations used in EPs could be most recommendable applied in the practical extruded pellet feeds for flounder grown from 114 g to 350 g.

• Journal of fish pathology
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• v.34 no.2
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• pp.185-199
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• 2021

Vibriosis is an important septicemic bacterial disease that affects a variety of commercial fish species, including cultured Dicentrarchus labrax. Nanotechnology has become an important modern tool for fish diseases prevention. Furthermore, nanomaterials have the ability to prevent and treat fish diseases. The current study was aimed to identify the causative agent of massive mortality of D. labrax commercial farm in Alexandria, Egypt. Experimental infection and the median lethal dose (LD50) of pathogenic isolate were assessed. Also, the effect of ginger nanoparticles (GNPs) and Sacchromyces cerevisiae as feed additives for prevention of vibriosis in D. labrax was carried out. Similarly, the tissue immunstimulant genes, IL-1β and TLR2 were measured in the spleen of feeding groups. The clinical signs of naturally diseased D. labrax showed corneal opacity and paleness of gills with excessive mucous secretion. The post-mortem abnormalities were severe hemorrhage and adhesion of internal organs. After bacteriological isolation and identification, the causative agent of mortality in the current study was Vibrio alginolyticus. The LD₅₀ of V. alginolyticus was 1.5×10^5.4 CFU/ml. The experimentally infected D. labrax showed ulceration, exophthalmia and skin hemorrhages. The post-mortem findings of the experimentally infected D. labrax revealed internal hemorrhage, spleen darkness and paleness of liver. There is no mortality and 100% RPS in groups fed GNPs then injected with V. alginolyticus, in those fed a combination of GNPs and S. cerevisiae and a group fed normal diet then injected with physiological saline (control negative), respectively. Contrarily, there was 10% mortality and 87.5 RPS in the group fed S. cerevisae then injected with V. alginolyticus. On the other hand, the control positive group showed 79% mortality. The spleen IL-1β and TLR2 immunostimulant genes were significantly increased in groups of fish fed GNNP, S. cerevisiae and a combination of GNPs and S. cerevisiae, respectively compared to control group. The highest stimulation of those immunostimulant genes was found in the group fed a combination of GNPs and S. cerevisiae, while fish fed S. cerevisiae had the lowest level. Dietary combination of GNPs and S. cerevisiae was shown to be efficient in preventing of vibriosis, with greatest stimulation of spleen IL-1β and TLR2 immunostimulant genes.

• Journal of the Korean Wood Science and Technology
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• v.48 no.4
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• pp.527-547
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• 2020

Fish pathogens cause not only economic damages to fish farming but also infectious pathogens known as a zoonotic agent. Since the continued use of antibiotics to control fish pathogens entails side effects, materials of natural origin need to be developed. The purpose of this study is to discover coniferous essential oils with excellent antibacterial effects in order to develop antibiotic alternatives. We have extracted essential oils using hydro-distillation from the leaves of Abies holophylla, Pinus thunbergii, Pinus parviflora, Tsuga sieboldii, and Pinus rigitaeda, which are all Pinaceae family. And, we have evaluated antibacterial activity with the extracted essential oils against Edwardsiella tarda, Photobacterium damselae, Streptococcus parauberis, and Lactococcus garvieae, which are fish pathogens. As a result, the essential oils from A. holophylla and P. thunbergii showed the selectively strong antibacterial activity against E. tarda and P. damselae, which are gram-negative bacteria. From GC-MS analysis, it was identified that main component of A. holophylla essential oils are (-)-bornyl acetate (29.45%), D-limonene (20.47%), and camphene (11.73%), and that of P. thunbergii essential oils is α-pinene (59.81%). In addition, we found three compounds: neryl acetate, (-)-borneol, and (-)-carveol, which are oxygenated monoterpenes. These exist in a very small amount but exhibit the same efficacy as essential oil. Therefore, we expect that A. holophylla and P. thunbergii essential oils having excellent growth inhibitory effect against gram-negative fish pathogens can be used as biological products such as feed additives and fishery products.

• Journal of Aquaculture
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• v.21 no.1
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• pp.26-33
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• 2008

This study investigated the synergistic effects of dietary supplementation of quartz porphyry(QP) and a laboratory developed feed stimulants, BAISM(BS) on growth performance and utilization as the additives for juvenile eel Anguilla japonica. Six isoenergetic experimental diets(18.2 kJ/g) were formulated to contain 50% crude protein, 15% lipid with or without dietary QP(Song-Gang stone, Davistone, Korea) and BS supplementation. QP and BS were provided at 0% in the control diet($Q_0B_0$) and at 0.7% QP+0% BS($Q_{0.7}B_0$), 0.7% QP+0.3% BS($Q_{0.7}B_{0.3}$), 0.7% QP+0.5% BS($Q_{0.7}B_{0.5}$), 0.7% QP+0.75% BS($Q_{0.7}B_{0.75}$) and 0.7% QP+1.0% BS($Q_{0.7}B_{1.0}$) in experimental diets on dry matter basis. After four weeks of adaptation, triplicate groups of 30 fish initially averaging $15{\pm}0.1g(mean{\pm}SD)$ were randomly distributed into each aquarium, and they were fed one of the experimental diets for 8 weeks. By the end of the feeding trial, weight gain(%), specific growth rate(%), feed efficiency(%) and protein efficiency ratio of fish fed diet $Q_{0.7}B_{0.5},\;Q_{0.7}B_{0.75}\;and\;Q_{0.7}B_{1.0}$, were significantly higher(P<0.05) than those of fish fed the other diets. But, $Q_{0.7}B_{0.5},\;Q_{0.7}B_{0.75}\;and\;Q_{0.7}B_{1.0}$ were no significant differences(P<0.05). In challenge test, fish were infected by intraperitoneal injection of 0.1 mL bacterial suspension with Edwardsiella tarda per fish after the feeding trial. As a result, fish fed QP and BS supplemented diets have a significantly higher cumulative survival rate than those of fish fed control diet(P<0.05). In conclusion, these results indicated that the optimum dietary supplementation level of QP and BS could be approximately 0.7% quartz porphyry+0.5% BAISM($Q_{0.7}B_{0.5}$) of diet based on WG, FER, SGR, PER, cumulative survival rate in juvenile eel A. japonica.

• Journal of fish pathology
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• v.36 no.2
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• pp.323-336
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• 2023

This study was conducted to find out the effect of yeast by-products discarded after beer production as feed additives for carp (Cyprinus carpio). After producing feed by adding high-temperature dried beer yeast by-products (HD), freeze-dried beer yeast by-products (FD), and freeze-dried fermented beer yeast by-products (FF) after lactobacilli fermentation, innate immunity indicators, survival rates, and challenge experiments were evaluated. Both ACH50 and lysozyme activity were significantly increased (p<0.05) in the experimental group of FF 0.2% and 0.5% compared to the control group from day 7 to day 21. In addition, phagocyte activity was significantly increased (p<0.05) in the group of FF 0.5% compared to the control group at all time points. Both IL-1β and TNF-α expression levels increased significantly in the FD and FF groups on day 21 compared to the control group (p<0.05). In addition, the FF 0.5% group showed significantly higher expression levels (p<0.05) at all time points. Similarly, IL-10 expression increased significantly (p<0.05) in FF 0.2% and 0.5% groups at all time points. SOD gene expression was significantly increased in FD 0.5% and all FF groups on day 14 and 21 (p<0.05). The results of a 10-day challenge experiment using Edwardsiella piscicida (E. piscicida) showed a higher relative survival rate than the control group at all concentrations that fed FD and FF. In summary, it is estimated that 0.5% FF can effectively improve the innate immunity, growth rate, and antibacterial properties of carp rather than using discarded beer yeast supernatant alone as a functional feed additive.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.5
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• pp.567-574
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• 2022

Immunostimulating effects of fucoidan administration to rockfish Sebastes schlegelii at a concentration of 20 g/kg of diet were evaluated under high water temperature condition. The oral administration of fucoidan mixed with feed at a concentration of 20 g/kg of diet for 2 weeks increased the interleukin 1β gene in the intestine and kidney of fish by 5.7 and 6.3 times, respectively. In addition, when the water temperature was gradually increased from 24 to 31.4℃ for 2 weeks, LT₅₀ delayed by 24 h in the fucoidan treated group compared to that in the control group, and mortality also reduced. Streptococcus iniae infection at a concentration of 1.50×10⁰ CFU/fish at 28℃ delayed LT₅₀ by 12 h in the fucoidan-treated group. Furthermore, the overall survival rate was 0% in the control group and 20% in the fucoidan-treated group. This study confirmed the applicability of dietary additives such as fucoidan as an immune activator of rockfish under high temperature condition.

• Korean Journal of Poultry Science
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• v.42 no.3
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• pp.247-256
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• 2015

There are approximately 1,500 broiler farms in Korea, each raising 55,000 birds. Ninety-five percent of the farms are contracted with Integration Company. According to the Korean broiler performance index, broilers in Korea are marketed at 32 days with 1.52 kg of body weight. In contrast, the market age and body weight of broilers are 47 days/2.8 kg in the United States and 42 days/2.5 kg in Europe. Because of the younger market age of the Korean broiler, the pre-starter feed is important. Chicks exhibit poor absorption of dietary nutrients up to 7 days after hatching due to an immature digestive system and low enzyme secretion rate and activity. At the beginning of hatching, chicks obtain their nutrients from the egg yolk sac. It is highly recommended that chicks, after consuming the nutrients in the egg yolk sac, are given supplemented pre-starter feed to increase early growth rates and improve the performance of broiler production. Pre-starter nutrient requirements are not expressed in NRC, so Korean feeding standards for poultry and commercial breeding companies determine the nutrient requirements of pre-starter broiler chickens. Three approaches are followed to formulate specially designed pre-starter feeds for broiler chicks: (i) selective use of raw materials, (ii) proper standards of nutrient supply, and (iii) application of feed additives such as exogenous enzymes. In the selection of raw materials, those with high digestibility can be used. The absorption rate of carbohydrates in grains can be increased through feed processing at high temperature and high pressure. Soy proteins and fish meal can also be added as protein sources. As an energy source, vegetable oils are preferred over animal fats because of the former's high digestibility. It is suggested that the levels of proteins and amino acids are higher in pre-starter feed than in starter feed. With regard to energy, the sources of energy are more important than the levels of energy in feed. Feed additives such as exogenous enzymes can be used to improve nutrient digestibility. In addition, organic acids and plant extracts can be used as alternatives to animal growth promoters to stimulate immunity and prevent diseases. The growth performance of broilers is affected by various factors, such as management and disease control, in addition to the nutritional strategy; however, nutritional strategies play an important role in improving the productivity of broilers. Therefore, nutritional strategies, along with management and disease control, are required for improving the productivity of broilers in Korea.